\begin{code}
module DsCCall
( dsCCall
+ , mkFCall
, unboxArg
, boxResult
- , wrapUnboxedValue
- , can'tSeeDataConsPanic
-
+ , resultWrapper
) where
#include "HsVersions.h"
import CoreSyn
import DsMonad
-import DsUtils
-import TcHsSyn ( maybeBoxedPrimType )
-import CoreUtils ( coreExprType )
-import Id ( Id, mkWildId )
-import Const ( Con(..) )
+import CoreUtils ( exprType, mkCoerce )
+import Id ( Id, mkWildId, idType )
+import MkId ( mkFCallId, realWorldPrimId, mkPrimOpId )
import Maybes ( maybeToBool )
-import PrelInfo ( packStringForCId )
+import ForeignCall ( ForeignCall(..), CCallSpec(..), CCallTarget(..), Safety, CCallConv(..) )
+import DataCon ( splitProductType_maybe, dataConSourceArity, dataConWrapId )
+import ForeignCall ( ForeignCall, CCallTarget(..) )
+
+import TcType ( tcSplitTyConApp_maybe )
+import Type ( Type, isUnLiftedType, mkFunTys, mkFunTy,
+ tyVarsOfType, mkForAllTys, mkTyConApp,
+ isPrimitiveType, eqType,
+ splitTyConApp_maybe, splitNewType_maybe
+ )
+
import PrimOp ( PrimOp(..) )
-import DataCon ( DataCon, dataConId, splitProductType_maybe )
-import CallConv
-import Type ( isUnLiftedType, splitAlgTyConApp_maybe, mkFunTys,
- splitTyConApp_maybe, Type
+import TysPrim ( realWorldStatePrimTy,
+ byteArrayPrimTyCon, mutableByteArrayPrimTyCon,
+ intPrimTy, foreignObjPrimTy
+ )
+import TyCon ( TyCon, tyConDataCons )
+import TysWiredIn ( unitDataConId,
+ unboxedSingletonDataCon, unboxedPairDataCon,
+ unboxedSingletonTyCon, unboxedPairTyCon,
+ trueDataCon, falseDataCon,
+ trueDataConId, falseDataConId
)
-import TysPrim ( byteArrayPrimTy, realWorldStatePrimTy,
- byteArrayPrimTyCon, mutableByteArrayPrimTyCon )
-import TysWiredIn ( unitDataCon, stringTy,
- unboxedPairDataCon,
- mkUnboxedTupleTy, unboxedTupleCon
+import Literal ( mkMachInt )
+import CStrings ( CLabelString )
+import PrelNames ( Unique, hasKey, ioTyConKey, boolTyConKey, unitTyConKey,
+ int8TyConKey, int16TyConKey, int32TyConKey,
+ word8TyConKey, word16TyConKey, word32TyConKey
)
+import VarSet ( varSetElems )
+import Constants ( wORD_SIZE)
import Outputable
\end{code}
\end{verbatim}
\begin{code}
-dsCCall :: FAST_STRING -- C routine to invoke
+dsCCall :: CLabelString -- C routine to invoke
-> [CoreExpr] -- Arguments (desugared)
- -> Bool -- True <=> might cause Haskell GC
+ -> Safety -- Safety of the call
-> Bool -- True <=> really a "_casm_"
- -> Type -- Type of the result (a boxed-prim IO type)
+ -> Type -- Type of the result: IO t
-> DsM CoreExpr
dsCCall lbl args may_gc is_asm result_ty
- = newSysLocalDs realWorldStatePrimTy `thenDs` \ old_s ->
-
- mapAndUnzipDs unboxArg args `thenDs` \ (unboxed_args, arg_wrappers) ->
- boxResult result_ty `thenDs` \ (final_result_ty, res_wrapper) ->
-
+ = mapAndUnzipDs unboxArg args `thenDs` \ (unboxed_args, arg_wrappers) ->
+ boxResult [] result_ty `thenDs` \ (ccall_result_ty, res_wrapper) ->
+ getUniqueDs `thenDs` \ uniq ->
let
- val_args = Var old_s : unboxed_args
- final_args = Type inst_ty : val_args
-
- -- A CCallOp has type (forall a. a), so we must instantiate
- -- it at the full type, including the state argument
- inst_ty = mkFunTys (map coreExprType val_args) final_result_ty
-
- the_ccall_op = CCallOp (Left lbl) is_asm may_gc cCallConv
- the_prim_app = mkPrimApp the_ccall_op final_args
-
- the_body = foldr ($) (res_wrapper the_prim_app) arg_wrappers
+ target | is_asm = CasmTarget lbl
+ | otherwise = StaticTarget lbl
+ the_fcall = CCall (CCallSpec target CCallConv may_gc)
+ the_prim_app = mkFCall uniq the_fcall unboxed_args ccall_result_ty
in
- returnDs (Lam old_s the_body)
+ returnDs (foldr ($) (res_wrapper the_prim_app) arg_wrappers)
+
+mkFCall :: Unique -> ForeignCall
+ -> [CoreExpr] -- Args
+ -> Type -- Result type
+ -> CoreExpr
+-- Construct the ccall. The only tricky bit is that the ccall Id should have
+-- no free vars, so if any of the arg tys do we must give it a polymorphic type.
+-- [I forget *why* it should have no free vars!]
+-- For example:
+-- mkCCall ... [s::StablePtr (a->b), x::Addr, c::Char]
+--
+-- Here we build a ccall thus
+-- (ccallid::(forall a b. StablePtr (a -> b) -> Addr -> Char -> IO Addr))
+-- a b s x c
+mkFCall uniq the_fcall val_args res_ty
+ = mkApps (mkVarApps (Var the_fcall_id) tyvars) val_args
+ where
+ arg_tys = map exprType val_args
+ body_ty = (mkFunTys arg_tys res_ty)
+ tyvars = varSetElems (tyVarsOfType body_ty)
+ ty = mkForAllTys tyvars body_ty
+ the_fcall_id = mkFCallId uniq the_fcall ty
\end{code}
\begin{code}
-> DsM (CoreExpr, -- To pass as the actual argument
CoreExpr -> CoreExpr -- Wrapper to unbox the arg
)
-unboxArg arg
+-- Example: if the arg is e::Int, unboxArg will return
+-- (x#::Int#, \W. case x of I# x# -> W)
+-- where W is a CoreExpr that probably mentions x#
- -- Primitive types
- -- ADR Question: can this ever be used? None of the PrimTypes are
- -- instances of the CCallable class.
- --
- -- SOF response:
- -- Oh yes they are, I've just added them :-) Having _ccall_ and _casm_
- -- that accept unboxed arguments is a Good Thing if you have a stub generator
- -- which generates the boiler-plate box-unbox code for you, i.e., it may help
- -- us nuke this very module :-)
- --
- | isUnLiftedType arg_ty
+unboxArg arg
+ -- Primtive types: nothing to unbox
+ | isPrimitiveType arg_ty
= returnDs (arg, \body -> body)
- -- Strings
- | arg_ty == stringTy
- -- ToDo (ADR): - allow synonyms of Strings too?
- = newSysLocalDs byteArrayPrimTy `thenDs` \ prim_arg ->
+ -- Recursive newtypes
+ | Just rep_ty <- splitNewType_maybe arg_ty
+ = unboxArg (mkCoerce rep_ty arg_ty arg)
+
+ -- Booleans
+ | Just (tc,_) <- splitTyConApp_maybe arg_ty,
+ tc `hasKey` boolTyConKey
+ = newSysLocalDs intPrimTy `thenDs` \ prim_arg ->
returnDs (Var prim_arg,
- \body -> Case (App (Var packStringForCId) arg)
- prim_arg [(DEFAULT,[],body)])
+ \ body -> Case (Case arg (mkWildId arg_ty)
+ [(DataAlt falseDataCon,[],mkIntLit 0),
+ (DataAlt trueDataCon, [],mkIntLit 1)])
+ prim_arg
+ [(DEFAULT,[],body)])
+
+ -- Data types with a single constructor, which has a single, primitive-typed arg
+ -- This deals with Int, Float etc
+ | is_product_type && data_con_arity == 1
+ = ASSERT(isUnLiftedType data_con_arg_ty1 ) -- Typechecker ensures this
+ newSysLocalDs arg_ty `thenDs` \ case_bndr ->
+ newSysLocalDs data_con_arg_ty1 `thenDs` \ prim_arg ->
+ returnDs (Var prim_arg,
+ \ body -> Case arg case_bndr [(DataAlt data_con,[prim_arg],body)]
+ )
-- Byte-arrays, both mutable and otherwise; hack warning
+ -- We're looking for values of type ByteArray, MutableByteArray
+ -- data ByteArray ix = ByteArray ix ix ByteArray#
+ -- data MutableByteArray s ix = MutableByteArray ix ix (MutableByteArray# s)
| is_product_type &&
- length data_con_arg_tys == 2 &&
- maybeToBool maybe_arg2_tycon &&
- (arg2_tycon == byteArrayPrimTyCon ||
- arg2_tycon == mutableByteArrayPrimTyCon)
+ data_con_arity == 3 &&
+ maybeToBool maybe_arg3_tycon &&
+ (arg3_tycon == byteArrayPrimTyCon ||
+ arg3_tycon == mutableByteArrayPrimTyCon)
-- and, of course, it is an instance of CCallable
= newSysLocalDs arg_ty `thenDs` \ case_bndr ->
- newSysLocalsDs data_con_arg_tys `thenDs` \ vars@[ixs_var, arr_cts_var] ->
+ newSysLocalsDs data_con_arg_tys `thenDs` \ vars@[l_var, r_var, arr_cts_var] ->
returnDs (Var arr_cts_var,
- \ body -> Case arg case_bndr [(DataCon data_con,vars,body)]
- )
-
- -- Data types with a single constructor, which has a single, primitive-typed arg
- | maybeToBool maybe_boxed_prim_arg_ty
- = newSysLocalDs arg_ty `thenDs` \ case_bndr ->
- newSysLocalDs the_prim_arg_ty `thenDs` \ prim_arg ->
- returnDs (Var prim_arg,
- \ body -> Case arg case_bndr [(DataCon box_data_con,[prim_arg],body)]
+ \ body -> Case arg case_bndr [(DataAlt data_con,vars,body)]
)
| otherwise
= getSrcLocDs `thenDs` \ l ->
pprPanic "unboxArg: " (ppr l <+> ppr arg_ty)
where
- arg_ty = coreExprType arg
-
- maybe_boxed_prim_arg_ty = maybeBoxedPrimType arg_ty
- (Just (box_data_con, the_prim_arg_ty)) = maybe_boxed_prim_arg_ty
-
- maybe_product_type = splitProductType_maybe arg_ty
- is_product_type = maybeToBool maybe_product_type
- Just (tycon, _, data_con, data_con_arg_tys) = maybe_product_type
- (data_con_arg_ty1 : data_con_arg_ty2 : _) = data_con_arg_tys
-
- maybe_arg2_tycon = splitTyConApp_maybe data_con_arg_ty2
- Just (arg2_tycon,_) = maybe_arg2_tycon
-
-can'tSeeDataConsPanic thing ty
- = pprPanic
- "ERROR: Can't see the data constructor(s) for _ccall_/_casm_/foreign declaration"
- (hcat [ text thing, text "; type: ", ppr ty
- , text "(try compiling with -fno-prune-tydecls ..)\n"])
+ arg_ty = exprType arg
+ maybe_product_type = splitProductType_maybe arg_ty
+ is_product_type = maybeToBool maybe_product_type
+ Just (_, _, data_con, data_con_arg_tys) = maybe_product_type
+ data_con_arity = dataConSourceArity data_con
+ (data_con_arg_ty1 : _) = data_con_arg_tys
+
+ (_ : _ : data_con_arg_ty3 : _) = data_con_arg_tys
+ maybe_arg3_tycon = splitTyConApp_maybe data_con_arg_ty3
+ Just (arg3_tycon,_) = maybe_arg3_tycon
\end{code}
\begin{code}
-boxResult :: Type -- Type of desired result
- -> DsM (Type, -- Type of the result of the ccall itself
- CoreExpr -> CoreExpr) -- Wrapper for the ccall
- -- to box the result
-boxResult result_ty
- -- Data types with a single nullary constructor
- | (maybeToBool maybe_product_type) && -- Data type
- (null data_con_arg_tys)
- =
- newSysLocalDs realWorldStatePrimTy `thenDs` \ prim_state_id ->
-{-
- wrapUnboxedValue result_ty `thenDs` \ (state_and_prim_datacon,
- state_and_prim_ty, prim_result_id, the_result) ->
- mkConDs ioOkDataCon
- [TyArg result_ty, VarArg (Var prim_state_id), VarArg the_result]
- `thenDs` \ the_pair ->
--}
- let
- the_pair = mkConApp unboxedPairDataCon
- [Type realWorldStatePrimTy, Type result_ty,
- Var prim_state_id,
- Con (DataCon unitDataCon) []]
- the_alt = (DataCon (unboxedTupleCon 1), [prim_state_id], the_pair)
- scrut_ty = mkUnboxedTupleTy 1 [realWorldStatePrimTy]
- in
- returnDs (scrut_ty, \prim_app -> Case prim_app (mkWildId scrut_ty) [the_alt]
- )
-
- -- Data types with a single constructor, which has a single, primitive-typed arg
- | (maybeToBool maybe_product_type) && -- Data type
- not (null data_con_arg_tys) && null other_args_tys && -- Just one arg
- isUnLiftedType the_prim_result_ty -- of primitive type
- =
- newSysLocalDs realWorldStatePrimTy `thenDs` \ prim_state_id ->
- newSysLocalDs the_prim_result_ty `thenDs` \ prim_result_id ->
- newSysLocalDs ccall_res_type `thenDs` \ case_bndr ->
-
- let
- the_result = mkConApp data_con (map Type tycon_arg_tys ++ [Var prim_result_id])
- the_pair = mkConApp unboxedPairDataCon
- [Type realWorldStatePrimTy, Type result_ty,
- Var prim_state_id, the_result]
- the_alt = (DataCon unboxedPairDataCon, [prim_state_id, prim_result_id], the_pair)
- in
- returnDs (ccall_res_type, \prim_app -> Case prim_app case_bndr [the_alt]
- )
-
- | otherwise
- = pprPanic "boxResult: " (ppr result_ty)
+boxResult :: [Id] -> Type -> DsM (Type, CoreExpr -> CoreExpr)
+
+-- Takes the result of the user-level ccall:
+-- either (IO t),
+-- or maybe just t for an side-effect-free call
+-- Returns a wrapper for the primitive ccall itself, along with the
+-- type of the result of the primitive ccall. This result type
+-- will be of the form
+-- State# RealWorld -> (# State# RealWorld, t' #)
+-- where t' is the unwrapped form of t. If t is simply (), then
+-- the result type will be
+-- State# RealWorld -> (# State# RealWorld #)
+
+-- Here is where we arrange that ForeignPtrs which are passed to a 'safe'
+-- foreign import don't get finalized until the call returns. For each
+-- argument of type ForeignObj# we arrange to touch# the argument after
+-- the call. The arg_ids passed in are the Ids passed to the actual ccall.
+
+boxResult arg_ids result_ty
+ = case tcSplitTyConApp_maybe result_ty of
+ -- This split absolutely has to be a tcSplit, because we must
+ -- see the IO type; and it's a newtype which is transparent to splitTyConApp.
+
+ -- The result is IO t, so wrap the result in an IO constructor
+ Just (io_tycon, [io_res_ty]) | io_tycon `hasKey` ioTyConKey
+ -> mk_alt return_result
+ (resultWrapper io_res_ty) `thenDs` \ (ccall_res_ty, the_alt) ->
+ newSysLocalDs realWorldStatePrimTy `thenDs` \ state_id ->
+ let
+ io_data_con = head (tyConDataCons io_tycon)
+ wrap = \ the_call ->
+ mkApps (Var (dataConWrapId io_data_con))
+ [ Type io_res_ty,
+ Lam state_id $
+ Case (App the_call (Var state_id))
+ (mkWildId ccall_res_ty)
+ [the_alt]
+ ]
+ in
+ returnDs (realWorldStatePrimTy `mkFunTy` ccall_res_ty, wrap)
+ where
+ return_result state ans = mkConApp unboxedPairDataCon
+ [Type realWorldStatePrimTy, Type io_res_ty,
+ state, ans]
+
+ -- It isn't, so do unsafePerformIO
+ -- It's not conveniently available, so we inline it
+ other -> mk_alt return_result
+ (resultWrapper result_ty) `thenDs` \ (ccall_res_ty, the_alt) ->
+ let
+ wrap = \ the_call -> Case (App the_call (Var realWorldPrimId))
+ (mkWildId ccall_res_ty)
+ [the_alt]
+ in
+ returnDs (realWorldStatePrimTy `mkFunTy` ccall_res_ty, wrap)
+ where
+ return_result state ans = ans
where
- maybe_product_type = splitProductType_maybe result_ty
- Just (tycon, tycon_arg_tys, data_con, data_con_arg_tys) = maybe_product_type
- (the_prim_result_ty : other_args_tys) = data_con_arg_tys
-
- ccall_res_type = mkUnboxedTupleTy 2 [realWorldStatePrimTy, the_prim_result_ty]
-
--- wrap up an unboxed value.
-wrapUnboxedValue :: Type -> DsM (Type, Id, CoreExpr)
-wrapUnboxedValue ty
- | (maybeToBool maybe_product_type) && -- Data type
- not (null data_con_arg_tys) && null other_args_tys && -- Just one arg
- isUnLiftedType the_prim_result_ty -- of primitive type
- =
- newSysLocalDs the_prim_result_ty `thenDs` \ prim_result_id ->
- let
- the_result = mkConApp data_con (map Type tycon_arg_tys ++ [Var prim_result_id])
+ mk_alt return_result (Nothing, wrap_result)
+ = -- The ccall returns ()
+ let
+ rhs_fun state_id = return_result (Var state_id)
+ (wrap_result (panic "boxResult"))
+ in
+ newSysLocalDs realWorldStatePrimTy `thenDs` \ state_id ->
+ mkTouches arg_ids state_id rhs_fun `thenDs` \ the_rhs ->
+ let
+ ccall_res_ty = mkTyConApp unboxedSingletonTyCon [realWorldStatePrimTy]
+ the_alt = (DataAlt unboxedSingletonDataCon, [state_id], the_rhs)
+ in
+ returnDs (ccall_res_ty, the_alt)
+
+ mk_alt return_result (Just prim_res_ty, wrap_result)
+ = -- The ccall returns a non-() value
+ newSysLocalDs prim_res_ty `thenDs` \ result_id ->
+ let
+ rhs_fun state_id = return_result (Var state_id)
+ (wrap_result (Var result_id))
+ in
+ newSysLocalDs realWorldStatePrimTy `thenDs` \ state_id ->
+ mkTouches arg_ids state_id rhs_fun `thenDs` \ the_rhs ->
+ let
+ ccall_res_ty = mkTyConApp unboxedPairTyCon [realWorldStatePrimTy, prim_res_ty]
+ the_alt = (DataAlt unboxedPairDataCon, [state_id, result_id], the_rhs)
+ in
+ returnDs (ccall_res_ty, the_alt)
+
+touchzh = mkPrimOpId TouchOp
+
+mkTouches [] s cont = returnDs (cont s)
+mkTouches (v:vs) s cont
+ | not (idType v `eqType` foreignObjPrimTy) = mkTouches vs s cont
+ | otherwise = newSysLocalDs realWorldStatePrimTy `thenDs` \s' ->
+ mkTouches vs s' cont `thenDs` \ rest ->
+ returnDs (Case (mkApps (Var touchzh) [Type foreignObjPrimTy,
+ Var v, Var s]) s'
+ [(DEFAULT, [], rest)])
+
+resultWrapper :: Type
+ -> (Maybe Type, -- Type of the expected result, if any
+ CoreExpr -> CoreExpr) -- Wrapper for the result
+resultWrapper result_ty
+ -- Base case 1: primitive types
+ | isPrimitiveType result_ty
+ = (Just result_ty, \e -> e)
+
+ -- Base case 2: the unit type ()
+ | Just (tc,_) <- maybe_tc_app, tc `hasKey` unitTyConKey
+ = (Nothing, \e -> Var unitDataConId)
+
+ -- Base case 3: the boolean type
+ | Just (tc,_) <- maybe_tc_app, tc `hasKey` boolTyConKey
+ = (Just intPrimTy, \e -> Case e (mkWildId intPrimTy)
+ [(DEFAULT ,[],Var trueDataConId ),
+ (LitAlt (mkMachInt 0),[],Var falseDataConId)])
+
+ -- Recursive newtypes
+ | Just rep_ty <- splitNewType_maybe result_ty
+ = let
+ (maybe_ty, wrapper) = resultWrapper rep_ty
in
- returnDs (ccall_res_type, prim_result_id, the_result)
-
- -- Data types with a single nullary constructor
- | (maybeToBool maybe_product_type) && -- Data type
- (null data_con_arg_tys)
- =
- let unit = dataConId unitDataCon
- scrut_ty = mkUnboxedTupleTy 1 [realWorldStatePrimTy]
+ (maybe_ty, \e -> mkCoerce result_ty rep_ty (wrapper e))
+
+ -- Data types with a single constructor, which has a single arg
+ | Just (tycon, tycon_arg_tys, data_con, data_con_arg_tys) <- splitProductType_maybe result_ty,
+ dataConSourceArity data_con == 1
+ = let
+ (maybe_ty, wrapper) = resultWrapper unwrapped_res_ty
+ (unwrapped_res_ty : _) = data_con_arg_tys
+ narrow_wrapper = maybeNarrow tycon
in
- returnDs (scrut_ty, unit, mkConApp unitDataCon [])
+ (maybe_ty, \e -> mkApps (Var (dataConWrapId data_con))
+ (map Type tycon_arg_tys ++ [wrapper (narrow_wrapper e)]))
| otherwise
- = pprPanic "boxResult: " (ppr ty)
- where
- maybe_product_type = splitProductType_maybe ty
- Just (tycon, tycon_arg_tys, data_con, data_con_arg_tys) = maybe_product_type
- (the_prim_result_ty : other_args_tys) = data_con_arg_tys
- ccall_res_type = mkUnboxedTupleTy 2 [realWorldStatePrimTy, the_prim_result_ty]
+ = pprPanic "resultWrapper" (ppr result_ty)
+ where
+ maybe_tc_app = splitTyConApp_maybe result_ty
+
+-- When the result of a foreign call is smaller than the word size, we
+-- need to sign- or zero-extend the result up to the word size. The C
+-- standard appears to say that this is the responsibility of the
+-- caller, not the callee.
+
+maybeNarrow :: TyCon -> (CoreExpr -> CoreExpr)
+maybeNarrow tycon
+ | tycon `hasKey` int8TyConKey = \e -> App (Var (mkPrimOpId Narrow8IntOp)) e
+ | tycon `hasKey` int16TyConKey = \e -> App (Var (mkPrimOpId Narrow16IntOp)) e
+ | tycon `hasKey` int32TyConKey
+ && wORD_SIZE > 4 = \e -> App (Var (mkPrimOpId Narrow32IntOp)) e
+
+ | tycon `hasKey` word8TyConKey = \e -> App (Var (mkPrimOpId Narrow8WordOp)) e
+ | tycon `hasKey` word16TyConKey = \e -> App (Var (mkPrimOpId Narrow16WordOp)) e
+ | tycon `hasKey` word32TyConKey
+ && wORD_SIZE > 4 = \e -> App (Var (mkPrimOpId Narrow32WordOp)) e
+ | otherwise = id
\end{code}
projects / ghc-hetmet.git / blobdiff